Typographer Pierre di Sciullo's Jour et Nuit. As succinct a manifestation I can find of RGB (additive) and CMYK (subtractive) colour. Play it here.
Significant too that in both cases the full 'saturation' of all colours fall as the counterform (the negative space within a letterform), a determinate factor in the design and signature-recognition of any form.
This, in turn, best illustrated by Emil Ruder in his seminal Typographie (1967).
Labels: Colour Process